Bank of locking switch-keys.



E. R. CORWIN & c. A. BALS. BANK OF LOOKING SWITGH KEYS. I LPPLIUATIOHFILED MAR. 28, 1908.

902,275. I Patented Oct. 27, 1908.

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In verziors:

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ELMER R. CORWIN AND CHARLES BALS, OF CHICAGO, ILLINOIS, ASSIGNORS 'lOCORWIN TELEPHONE MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS,ACORPORATION 'OF ILLINOIS.

BANK OF LOGKIN G SWITCH-ICEYS.

ivo. 902,275. Specification of Letters Patent. Patented Oct. 27, 1908.

I Application filed March 28, 1908. Serial N 0. 423,885.

To allv whom it may concern: v a plunger 36 made of insulating material,for

Be it known that we, ELMER R. CORWIN l operating the said contactmembers, eachofi and Crmnens A"."BALs, both unansorthb thepliingers 3636 being connected by a ver- United States of America, and residents oftical bar 37 which extends through the top Chicago, Cook county,Illinois, have invented plate 35, with a push-button 38 the dep'resa newand useful'Bank of Looking Switchsion of which depresses the plunger 3.6and Keys, of which the following is a specificathereby operates theswitch-contact memtion, reference being bad to the accompanybers as willbe hereinafter described. Each ing drawings illustrating same. of theplungers 36 36 has a rod 7 extending Our invention relates to banks ofswitch keys of the push-button type, wherein any into one of the strips33 33, referably as spring 8 encircling same to automatically raise theplunger 36 out of connection with the corresponding set ofspring-contact members when the push-button 38 and the bar 37 allylocked in depressed position, the de ression of any other push-button ofthe bank releasing the first depressed push-button, the last depressedpush-button being automatically looked in depressed position until rearereleased. To accommodate the rods 7 7 l push-button that is depressed isautomatici shown in Fig. 2, the said rod 7 aving a coil leased by thedepression of another pushi the strips 33 33 are drilled on their topedges button. with holes slightly larger than the rods 7 7,

The principal objects of our invention are and with larger holes 9 9extending upfrom to provide a simplified construction in such the bottomedges thereof to meet the smaller a bank of locking keys to provide animholes at the top edges, to form bearings for proved arrangement forautomatically operthe rods 7 7 at the top edges only of the ating thelocking bars of the several keys of strips 33 33. I This construction inthe stri s I the bank; to provide an improved ringing ar- 33 33 gives afree action to the rods 7 7, as t 1e rangement for each of the keys ofthe bank; latter do not bear against the interior porv to provideimproved means for operating the tions of the strips 3333 along theentire several phu'igers of thervarious keys of the length of theinserted end portions of the bank, upon their release by the variouslockrods 7 7. ing bars; to provide improved means for The top plate 35is provided with suitable numbering or lettering each of the keys ofholes 10 10 for mounting the bank in place. the bank and to provideimproved means On the underneath side of the plate 35 is se- Whereby theoperation of the various keys, cured a strip 11 of felt, or some otherpliable when released, is practically noiseless. material, for deadeningthe sound of the therethrough, from the corresponding bar 37 5 I Otherobjects will be apparent from the striking of the collars 12 12 of thebars 37 37 following specification. when the latter are released andforced up- .In the drawings, Figure 1 is a side eleva ward b the coilsprings 8 8. The collars 12 tion of a bank of locking switch keys con12, pro erably formed of sheet metal and each structed in accordancewith the p'resent'in having a tongue portion 32 riveted to the vention,with portions shown in cross-section corresponding bar 37, are securedaroundthe to show the interior construction of the appabars 3-7 37underneath the felt strip 11 to ratus; Fig. 2 is a right-hand end Viewof the limit the upward movement of the push-butbank of switch keysshown in Fig. 1, with tons 38 38, when the bars 37 37 are released.portions shown in cross-section to show the It will readily be seen thatthe felt strip 11 interior construction of the apparatus; and Fig. 3 isa plan view of the bank of switch 37 37 noiseless, as it forms a cushionfor each keys shown in Figs. 1 and 2,. Like characof the collars 12 12when the bars 37.37 are tors refer to like parts in the several figures.I released. I Y,

The bank of keys illustrated comprises one I Each of the group of switchcontacts comor more spring-contact mounting strips prises spring members13, 14, 15, 16 and 17, carried by formed'sheet-metal portions 34 34 Ithe spring members 15and 16 being adapted secured to the ends of thestrips33 33 and to to enga e the spring members 14 and 17, rethe topplate 35, preferablyby screws. Each spectivel when the correspondingplunger of thest-rips 33 33 carries a plurality of sets 36 is depressedto locking osition, and the v of spring-contact members, each sethavingspring member 14 being ar apted to engage no practical ymakes theoperation .of the bars ice which is mounted to one plurality oftransverse ss ss oi the .to move the side bars 2O 20, as a unit, in thedirection 01 arrow the spring member 13 when the plunger 36 is depressedstill further. The spring member 15 is made somewhat longer than thespring member 16, so that it will. engage the Llargc upper portion 18 ofthe plunger 36 be- -fore the spring member 16 would engage the portion18 it the plunger 36 were depressed far enough, so as to throw thespring member 14 into contact with the spring member 1.3 withoutoperating the spring members 16 and 17 after they have come into contactwith each other. This construction gives an easier action to thepush-buttons 38 38 when same are depressed to cause the spring members14 14 to engage the respective spring members 13 13.

The sheet-metal end portions provided with notches near their upper ends111 which are s'lidably mounted longitudinal side bars 19 19, the latterbeing locking bars 29 39 suitably riveted to the side bars 19 19. Eachof the transverse bars 20 20 is for lockin one or more oi" thepush-button keys bank in depressed position.

Each of the bars 37 Wis provided with two notches 21 22 therein, toaccommodate the corresponding locking bar 20, the latter notch 22 beingbeveled at its upper edge to permit the depression of the push-button 38bars 19 19 and the locking 28, against the act-ion oi-the lca'l' spring24 of the end portions 34 and which bears against the transverse bar 25carried by the side bars 19 19. The transverse bar 25 is preferablysimilar to the locking bars 20 20. The end strip 3 1 to which the springmember 24 is mounted is provided with a set screw- 26 and a lock nutthereon, which set screw may be adjusted through the strip 34 againstthe s ring member 24 to adjust the tension. ot the latter against thebar 25 as desired.

. y The depression ot any one 01' the push-bun tons 3 33 causes thebeveled portion oi" the lower notch 22 oi the corresponding bar 37 toengage the corresponding locking bar 20 and thereby move the side bars19 19 and the locking bars 20 20 as a. whole in the direction 01' arrow23 until the locking bar 1291s able to drop into the notch 11 andthereby allow the spring member i l to .lorco the side bars 19 19 andthe locking bars J9 ".39 as a whole in the direction 01' arrow 37 sothat the locking bar 39 rests in the notch 21 ot the dc pressed pushbutton key. in this locked position the spring members 15 and 16 ot thedepressed key cngz'ige the contact. members 14 and 17, respectively, butthe contact mcmer 1a does not engage the contact member 13. llthedepressed. key is now further dc pressed. the contact member 14 willbe caused to engage the contact member 13. In telephone systems thislatter depression 01' the 34 34 are held together by a key generallycloses a ringing circuit, while the former depression of the key, or thedepression to locking position, generally closes a talking circuit. Now,it any of the other keys of the bank is depressed to locking position,as just described, the side bars 19 19 and the locking bars 20 20 willbe moved as a whole by such depression in the direction oi arrow 23 sothat the locked key will be released and forced by the correspondin coilspring 8 to the position shown 1n the rawi ings, the latter depressedkey now being l locked by its locking bar 20 in a depressed l position.It will readily be seen that by this construction the depression of anyone of the keys of the bank to locking position will release any of theother keys of the bank which i have previously been locked in depressedpo sit-ion, and. that any 01'' the keys of the bank, whether locked ornot, can be still ltll'tllOl depressed to a position which causes thecorrespending contact member 14 to engage the contact member 13 of thekey.

For numbering each of the push-lnitton keys 38 38 animal cap provided,to lit over a head 29on the corresponding bar 37 to hold a number disk39 and a transparent disk 31 in place, prcl'era bly as shown in Fig. 1.This construction permits olreadily removing or changing the nun'ibersoi the va- 95 rious keys ol the bank, which a very dcsirablc feature inintcrcommunicating telephone systcnis where the iinnibcrs of the variouskeys at the several stations have to be arranged to correspond with thenumbers of 100 the lines or stations of the system.

The spring-contact members 13, 1 1, 15, 16 and 17 of the various keys ofthe bank are all suit-ably mounted to die strips 33 33 by screws orbolts, and are insulated from each 10! other and from the stri s 33 bysuitable insulating washers and ushings 39.

The wiring for the various keys of the bank is connected to theconnection terminals provided at the lower ends of the variousspringcontact members of the several keys.

We do not wish to limit this invention to herein shown, as manymodifications may be made therein without departing from the 11 scope ofthe appended claims.

\ What we claim as our invention l 1. A bank ol switch keys cinnprisinga plul rality ol' push-buttons, a plunger for each ol l the push-buttonsadapted to be 0 erated l2 thereby, a set of spring-cont act mem )ers foreach of the plungcrs adapted and arranged to be controlled thereby, avertical bar for each of the keys connecting the push-lnitton with theplunger, notches in each of the said vertical bars, one being beveled atits upper surface, a plurality of longitudinal side barsslidablymounted, a plurality of transverse locking bars carried bythesaid side bars, the

l bars being adapted to normally 1ft said locking .said locklng' barsand said side bars as a unit whereby any of the push-button keys whichI. to control respective switch said vertical bars.

rest'in the notches of'the'said vertical bars, I transverse bar of thelocking bar unit to opa leaf spring near one end of the bank of keys Ierate the latter when released by the depres} adapted to bear againstone of the said transsion of any of the said plungers, and an ad versebars for forcing the latter as a. unit into j ustment screw for the saidleaf spring wherethe said notchesof-the said vertical bars, and 1 by thetension of same actin a coil spring acting on each of the said plunllocking bar unit may be adjusted as desired. gers to operate-same whenthe latter are re-' l 3. A switch key of the character described eased,the depression of any one ol the push-. comprising a nonconduetingplunger, switchuttons causmg the beveled surface of the I be operated bynotch associated therewith to operate the 1 the plunger, switchesadaptedtobecontrolled so as to disengage the said locking bars from 5the various notches of the said vertical bars operates both of theswitch-co V L es, and means may have been in depressed position are relvhereby a stillfurther depression of the plunleased, the saidpush-button which is being epressed being automatically locked. indepressed position when depressed i'arenough l to allow the said lockingbars to be forced by I thesaid leaf spring into the notches of thesu'bsl'aribe our names in t1 mom hers still further to control anadditional switch.

1e presence of two subscribing Witnesses; this 25th day of M arch,

2. A bank of locking switch keys having a I 1908 pluralityoflongitudinal sidebars and a plu- ELMER' R; CORVYIN. rality of transverselocking bars comprising r GHARLESA; BALS. a unit, operable as such, aplurality of plun- Witnesses:

gels in looking relation with the saidtransl HARRY B. DAVIS, verselocking bars, a leaf spring acting on a l FRANK J. RYAN.

by the switchcontact members, meansger operates only one of theswitch-contact As inventors of theforegoing wehercunto

